Some rail season ticket holders will face fare rises of almost 6% in January, it was revealed today.

An annual ticket from Canterbury in Kent to London will be going up from £4,588 to £4,860 - a 4.9% rise, according to figures from rail customer watchdog, Passenger Focus.

Some other Kent travellers - those buying season tickets from Tonbridge to London - will face a 4.4% rise from January 2, with their fare going up to £3,796.

Regulated fares, which include season tickets, will rise by an average of 4.2% from January.

Other fares picked out by Passenger Focus today that will rise above this 4.2% average include Northampton to London (up 4.7% to £4,980); Morpeth to Newcastle-upon-Tyne (up 5.0% to £1,008) and Llanelli to Swansea (up 5.4% to £624).

Other above-average rises highlighted by Passenger Focus are Bangor-Llandudno (up 5.2% to £1,140) and Ludlow to Hereford (up 5.3% to £1,192).

Some season tickets are not rising as much as 4.2%, while others are on, or very close, to the average.

The cost of a season from Shenfield in Essex to London, for example, actually dips in price, from £2,720 to £2,704, while an Ellesmere Port to Chester annual ticket is rising only 2.3% to £720.

Among season ticket fares that are rising by less than 4.0% are Aylesbury-London (up 3.2%), Cambridge-London (up 3.8%), Tain-Inverness (up 3.8%) and Stirling-Glasgow (up 3.9%).

The rises could have been steeper but for an intervention by the Government to limit the regulated fare rise to RPI inflation (as of July 2012) plus 1%, rather than the planned RPI plus 3% increase.

Train companies have the flexibility to raise some season tickets above the 4.2% ceiling as long as the average increase on their trains is no more than 4.2%.

Passenger Focus said that it appeared that train companies were exercising restraint but added that the price rises will still feel steep in some places.

"After years of above-inflation fare rises, fresh increases are piling pressure on already high fares. The Government and the rail industry must now work together to deliver on the welcome promise to get fare rises in line with inflation."

Regulated fares account for around 40% of total fares. Train companies can raise non-regulated fares by as much as they like. Details of all fare rises are expected in the next few days.

A spokesman for the Association of Train Operating Companies said: "It is the Government, not train companies, that decides how much season tickets should rise on average each year.

"Successive governments have instructed train companies every year to increase these regulated fares on average by more than inflation.

"In doing so, ministers have been seeking to cut the contribution from taxpayers towards the running costs of the railway and increase the share that comes from passengers."

Manuel Cortes, leader of the TSSA rail union, said: "Thousands of commuters across south east England will be paying more than £5,000 a year for their season tickets because of the Government's unfair annual inflation-plus fare rises.

"From Bedford in the north to Battle in the south, these are the huge sums hard-pressed families have to find just to get to work each day.

"Conservative and Lib Dem MPs have their own fares paid for by the taxpayer. If they didn't, they would not be so willing to vote for such intolerable fare hikes."

Rail Minister Norman Baker said: "Family budgets are being squeezed, so that is why this Coalition Government has taken pro-active steps to cut the planned fare rises from 3% to 1% above inflation until 2014.

"This decision puts an average of £45 per year back into the pockets of over a quarter of a million annual season ticket holders. Many more holders of weekly and monthly season tickets could also see lower fare rises and some commuters could be over £100 better off.

"It is misleading to search for the highest increase and then imply that represents the average, as some I am afraid will do. It's worth noting that some fares, such as the season ticket from Shenfield to London, are actually going down."

RMT general secretary Bob Crow said: "Train companies, with the collusion of the Government, will be jacking up fares by up to 6% in the new year as they launch a full-frontal assault on passengers in the name of profit.

"RMT will turn the poisonous cocktail of fare increases and job cuts into a political campaign that will come back to haunt this rotten Government."